Secular changes in prediabetes indicators among older-adult Americans, 1999-2010.
Level 4 - case-series / case-control
Serial cross-sectional analysis of representative national survey data (NHANES)
PubMed 25601724 · doi:10.1016/j.amepre.2014.10.004
What was done
Researchers analyzed data from 7,995 civilian, non-institutionalized US adults aged ≥50 years from the 1999–2010 National Health and Nutrition Examination Survey (NHANES). Prediabetes was defined as HbA1c 5.7%–6.4% (39–47 mmol/mol [HbA1c5.7]), fasting plasma glucose 100–125 mg/dL (impaired fasting glucose [IFG]), or both. Crude and multivariable-adjusted prevalences were calculated across two time periods (1999–2005 vs 2006–2010) across age brackets (50–64, 65–74, ≥75 years) and sex, adjusting for sociodemographics, living alone, and BMI.
What was found
From 1999–2005 to 2006–2010, prediabetes increased significantly in adults aged 50–64 years (38.5% [95% CI: 35.3, 41.8] to 45.9% [95% CI: 42.3, 49.5], p=0.003) and 65–74 years (41.3% [95% CI: 37.2, 45.5] to 47.9% [95% CI: 44.5, 51.3], p=0.016), but the change was not significant for adults aged ≥75 years (45.1% [95% CI: 41.1, 49.1] to 48.9% [95% CI: 45.2, 52.6], p>0.05). Prediabetes increased significantly for women in the two younger age groups, and HbA1c5.7 increased for both sexes (except men aged ≥75 years), while IFG remained stable across sexes. Men had higher prevalences than women for prediabetes and IFG at ages 50–64, and for IFG at ages ≥75.
Why it matters
Nearly half of older American adults met prediabetes criteria by 2010, with rising rates driven primarily by shifting HbA1c distributions rather than fasting glucose. It highlights older adults, particularly women, as growing targets for metabolic intervention.
Limits
The study is cross-sectional, precluding causal inference or tracking progression to overt diabetes. Institutionalized older adults were excluded, potentially skewing estimates in the oldest age group. Oral glucose tolerance testing was not assessed, and reliance on single-timepoint laboratory measures may misclassify glycemic status.
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- supports A higher percentage of men in the US have pre-diabetes compared to women.